• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.7
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• pp.3369-3385
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• 2019

There are various research challenges in vehicular ad hoc networks (VANETs) that need to be focused until an extensive deployment of it becomes conceivable. Design and development of a scalable routing algorithm for VANETs is one of the critical issue due to frequent path disruptions caused by the vehicle's mobility. This study aims to provide a novel road-aware routing protocol for vehicular networks named as Two-level hierarchical Hybrid Road-Aware (THERA) routing for vehicular ad hoc networks. The proposed protocol is designed explicitly for inter-vehicle communication. In THERA, roads are distributed into non-overlapping road segments to reduce the routing overhead. Unlike other protocols, discovery process does not flood the network with packet broadcasts. Instead, THERA uses the concept of Gateway Vehicles (GV) for the discovery process. In addition, a route between source and destination is flexible to changing topology, as THERA only requires road segment ID and destination ID for the communication. Furthermore, Road-Aware routing reduces the traffic congestion, bypasses the single point of failure, and facilitates the network management. Finally yet importantly, this paper also proposes a probabilistical model to estimate a path duration for each road segment using the highway mobility model. The flexibility of the proposed protocol is evaluated by performing extensive simulations in NS3. We have used SUMO simulator to generate real time vehicular traffic on the roads of Gangnam, South Korea. Comparative analysis of the results confirm that routing overhead for maintaining the network topology is smaller than few previously proposed routing algorithms.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.34-41
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• 2008

Existing mobility support scheme like MIPv4 has the delay at data transfer and Triangle routing problem. This paper proposes the new mobility support scheme and method that can overcome the problem using MPLS LSP in Next Generation Network. The proposed scheme overcomes the problem by introducing the LMS(Location Management Server) managing the location of the mobile terminal and the MPLS LSP between FA for a tunneling. We shows on the mathematical analysis using the queuing theory that this proposed scheme is more superior to the existing method(MIP).

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1189-1193
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• 2010

Mobility management is one of the most important research issues in 6LoWPAN, Since the IP-WSN application domain is expanded to real-time applications such as healthcare and surveillance systems, a fast and seamless handover becomes an important criterion in 6LoWPAN. However, a draft of IETF 6LoWPAN WG for mobility support does not decrease handover delay. Although LoWMob supports a fast intra-PAN handover. it can be supported when the infrastructure node has the location information of the other nodes in the mobile node's moving direction. In this paper, we propose a fast and seamless mobility protocol to support intra-PAN handover, named intra-MARIO. In intra-MARIO, a parent node of the mobile node preconfigures its handover to the PAN when the parent node detects its movement, thereby reducing the handover delay. Since intra-MARIO also supports route optimization, the mobile node can communicate with its corresponding nodes through the optimal route. In this paper, we analysis the signaling cost and evaluates that the handover can be completed in 20ms by simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.11
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• pp.35-43
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• 2011

In this paper, we propose a novel architecture for seamless mobility management to provide users with seamless Internet connection when users roam between diverse wireless local area networks (WLANS) controlled by different management entities. There have been many researches in IETF, i.e., MIPv6, HMIPv6, and PMIPv6, to provide the mobility management. However, practically since wireless access points or access routers, which are managed by an individual manager or ISP managers, have different authentication scheme and the supported mobility management, the previous mobility management protocol developed by IETF can not guarantee the quality of service of application services as the mobile node performs the handover. To solve this drawback, we propose the mobility management scheme to provide QoS-guaranteed Internet services during the handover by configurating the wireless networks which is defined by users. More specifically, we present a model, the architecture and an algorithm for user-defined network (UDN) to provide the seamless Internet service. Finally, the performance of the proposed algorithm is evaluated by the network simulation tool.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.82-89
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• 2011

The Proxy Mobile IPv6 is a network-based localized mobility management protocol. In the PMIPv6, Mobile Nodes are topologically anchored at a Local Mobility Anchor, which forwards all data packets for registered Mobile Nodes. Since all data packets destined for the Mobile Nodes a1ways traverse the Mobile Nodes's Local Mobility Anchor, the LMA might be bottleneck and the end-to-end de1ay are increased. Therefore, in this paper, we proposed an enhanced Route Optimization scheme in Multiple Local Mobility Anchors environment. In order to rapid1y detect Route Optimization, we designed Domain Information Table in Mobility Access Gateway. Furthermore, we use Correspondent Binding Cache in Local Mobility Anchor to maintain Route Optimization information during Mobile Nodes's handover. To solve packet loss and reodering problems during handover, we propose a new buffering and forwarding scheme.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.445-448
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• 2003

During a time when cellular systems are being deployed in massive scale worldwide, international roaming is becoming increasingly important. This paper presents UIM (User Identification Module) for mobility support, authentication, and service portability between different mobile systems. We also introduce network model based on PASM(Portable Authentication and Mobility Service Machine) which will support signaling protocol and user information conversions with database for roaming between different mobile networks. Stored data types and elements in UIM, logical data structure and configuration, and registration procedures are described here in the case of DCN (Digital CDMA (Code Division Multiple Access) Network System) and GSM (Global System for Mobile Communications).

• Electronics and Telecommunications Trends
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• v.31 no.1
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• pp.14-24
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• 2016

최근 ITU-R의 5G 서비스 및 성능 요구사항의 기준을 시작으로 각 표준화 단체 및 국가에서는 2020년을 목표로 5G에 대한 연구가 활발히 이루어지고 있다. 이 논문은 5G 서비스 및 기술적인 요구사항을 충족시킬 수 있는 네트워크 구조의 동향에 대해 살펴보고, 특히 5G 네트워크를 위한 이동성 관리 기술동향을 소개한다. 또한, 기존 4G 네트워크의 중앙집중형 이동성 관리 기술이 5G 서비스를 제공하는 데에 어떤 단점이 있을지에 관해 기술한 다음, 분산형, 평면형 이동성 관리 기술로 대표적인 Locator-Identifier Separation Protocol(LISP)과 Distributed Mobility Management(DMM) 기술을 소개하여, 각 이동성 관리 기술의 특징 및 장단점을 비교한다. 마지막으로, 5G에서의 이동성 관리 기술 요구사항을 도출하여, LISP과 DMM의 적용 가능성을 분석하여 최적의 5G 이동성 관리 기술을 도출하는 데 도움을 주고자 한다.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.503-508
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• 2007

Since the Wibro service realize mobile network on the public, it has been considered that it is not enough to support real time service at vehicular speed. The standard Fast Mobile IPv6 Handover Protocol using HMIPv6 may guarantee seamless service as long as the Mobile Node moves in the same domain MAP however it does not regard fast handover over inter-MAP domain. Thus Macro Mobility Handover in HMIPv6 was proposed to reduce handover latency in inter-MAP domain. But it is still not enough to support real-time service. So we propose an Improved FHMIPv6 over 802.16e network to reduce the overall handover latency. We embedded Layer 3 handover messages of the FHMIPv6 into the Layer 2 handover messages. So the MN is able to $^-nish$ overall handover procedure earlier in our scheme. The numerical results show the performance of IFHMIPv6 has improved about 32% in comparison with FHMIPv6.

• Journal of Advanced Navigation Technology
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• v.14 no.4
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• pp.537-544
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• 2010

The PMIPv6 is a network controlled mobility management protocol in which mobile nodes never participate in IP mobility protocol signaling. One issue in using PMIPv6 for multicast service is that a new component should be added as the mobility management functions are located not on the device but on the network. Currently, standardization activities for providing muticast services with PMIPv6 have been actively in progress. This paper addresses some issues about the on-going standardization works for providing efficient real-time multicast services with PMIPv6, and proposes a scheme for minimizing hand over delays and packet losses by using a new neighbor cell reporting method. The proposed scheme has been verified to outperform the existing scheme in hand over delay and packet loss perfonnrmces by using computer simulations.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.138-147
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• 2003

There are some problems of current internet protocols to support the mobility of terminal in wireless environments. The mobile IP has come out to solve these problems, but there exists some problems like triangle routing, the need of each host's home address and the management of tunneling. Also. real-time multimedia traffics require fast hand-off, low latency and the utilization ratio of high bandwidth. SIP can support the mobility of wireless terminal and is widely accepted as the protocol which can support multimedia service and call setup in next generation network. In this paper, the framework of SIP system will be designed and implemented to support the mobility of wireless terminal by using JAIN API which follow the standards of next generation network and this system matches the standards of next generation network.